The present invention generally relates to multi-function fluid treatment systems, and more particularly to a fluid treatment system which is capable of (1) high-efficiency, low maintenance filtration of fluid materials containing suspended solids; and (2) rapid and complete dissolution of a selected gas within a fluid material. The functional capabilities of the fluid treatment system described herein will depending on the specific system configuration and manner in which the system is used. Regardless of which function is selected in accordance with the present invention, a common feature of importance involves the use of multiple rotating cartridge units for filtration or gas introduction purposes as discussed below.
Regarding the separation of solid materials from fluids, fluid treatment systems play an important role in a wide variety of industrial and commercial processes. In addition, high efficiency fluid treatment systems are currently being using in numerous medical applications, including but not limited to blood filtration and the separation of microorganisms (e.g. bacteria) from biological or other fluids. Accordingly, recent advances in separation technology have created fluid treatment systems which are capable of removing solid materials of a very small size from selected liquids. Many of these systems involve the use of a sophisticated membrane structure associated with a cylindrical cartridge unit. Membrane-type cartridge units are basically described in U.S. Pat. Nos. 4,790,942; 4,867,878; 4,876,013; 4,906,379; 4,911,847; and 5,000,848. All of these references disclose single, membrane-type rotating cartridge units and/or components associated therewith.
Notwithstanding the foregoing filtration units and components, a need exists for a fluid treatment system which is capable of removing substantial quantities of solid materials from liquids or slurries having large amounts of solids therein. When the filtration of these materials is attempted using conventional filter systems, filtration efficiency decreases substantially for numerous reasons. Primarily, the exposed surfaces of the filtration media become clogged or blocked with solid materials, thereby slowing the separation process and decreasing filter life. This situation also results in decreased filtration capacity due to a continuing need to deactivate and clean the filter system. As a result, the volume of fluid materials to be treated within a given time period is minimized. Problems of this nature typically occur in a wide variety of situations involving many types of liquid or slurry materials including but not limited to yeast slurries and beer test samples in the brewing industry, petroleum products, dairy by-products, medical compositions and the like.
The present invention represents a unique, self-cleaning fluid treatment system which is characterized by a high degree of operating efficiency. The invention specifically involves a specialized filtration apparatus which enables the removal of solid materials from liquids having a high concentration of suspended solids. Also, large volumes of liquid materials may be filtered in a minimal amount of time. These goals are accomplished while avoiding the problems listed above. The present invention therefore represents an advance in the art of high efficiency filtration.
Aside from the filtration of fluid materials, another important function encompassed within the term "fluid treatment" as used herein involves the injection and dissolution of gaseous materials into liquids. For example, in the production of beverage products (e.g. beer, ales, sweetened soft drinks, non-beer alcohol-containing malt beverage compositions and the like), it is often necessary to carbonate such materials with gaseous CO.sub.2 to produce beverage products with desired taste characteristics. Other situations which involve the dissolution of gaseous materials into fluids include but are not limited to (1) the introduction of O.sub.2 into compositions used to produce fermented food/beverage materials (e.g. the infusion of O.sub.2 into "wort" used in beer production); (2) the introduction of air or O.sub.2 into waste materials (e.g. sewage) for aerobic digestion within waste treatment plants; (3) the introduction of ozone (O.sub.3) into water materials for the purification thereof (e.g. the destruction of microorganisms); and (4) the infusion of air or O.sub.2 into water used to support fish and other aquatic life forms. In this regard, the present invention shall not limited to any applications or materials which are used to produce a gas-containing liquid product as discussed below.
A need currently exists for a high-efficiency gas introduction system in which gases are placed in intimate contact with a selected fluid to achieve complete gas dissolution within the fluid. This need is especially important in the beverage industry where rapid gas introduction/dissolution is required with a minimal amount of system down-time needed to perform cleaning and other maintenance activities. For example, during the processing and carbonation of beverage materials (e.g. beer) suspended organic solids and other related compositions can result in the production of a "bio-film" layer (comprised of organic film-forming compositions) on conventional stationary carbonation equipment, thereby causing cloggage and a reduction in operating efficiency. The present invention solves these problems and enables the rapid and efficient delivery of gaseous materials in a manner which (1) avoids the build-up of extraneous solids on system components; (2) enables the diffusion of gaseous materials within a selected fluid in a rapid and evenly-distributed manner; and (3) creates a high degree of fluid turbulence in the system which facilitates the introduction and dissolution of large quantities of gaseous materials into a selected fluid in a minimal amount of time. Accordingly, the present invention represents an advance in the art of fluid treatment in that it not only enables fluids to be filtered in a highly efficient manner, but likewise facilitates the dissolution of gaseous materials within fluids depending on the operating mode of the system. In this regard, the invention represents a true multi-function fluid treatment system of novel design and capabilities as discussed below.